Typically, ink jet printing involves forming characters on a substrate by ejecting ink droplets from a printhead having one or more nozzles. In order to provide a high quality image, hot melt jet ink compositions which are solid at room temperature, but molten at jetting temperature are used. Unfortunately, such hot-melt jet ink compositions, while capable of providing a high quality image, are readily abraded or deformed upon handling of the printed substrate. Such abrasion and lack of adherence is a problem not only when printing onto porous substrates, such as paper, but is particularly troublesome when applying hot-melt jet ink compositions to nonporous substrates, such as plastic films and coated or noncoated containers.
European Published Application No. 0 475 707 discloses hot melt jet ink compositions containing polyester resins having acid numbers in the range from 1 to 54 and proposes the use of resins having an acid number of 10 or more in combination with mono-and dialkylbenzene-sulfonamides. Such sulfonamides, however, are often incompatible with other hot melt jet ink ingredients.